Microelectronic imaging units and methods of manufacturing microelectronic imaging units

ABSTRACT

Methods for manufacturing microelectronic imaging units and microelectronic imaging units that are formed using such methods are disclosed herein. In one embodiment, a method includes providing a plurality of imaging dies on a microfeature workpiece. The individual imaging dies include an image sensor, an integrated circuit operably coupled to the image sensor, and a plurality of external contacts operably coupled to the integrated circuit. The method further includes attaching a plurality of covers to corresponding imaging dies, cutting the microfeature workpiece to singulate the imaging dies, and coupling the singulated dies to a support member. The covers can be attached to the imaging dies before or after the workpiece is cut.

TECHNICAL FIELD

The present invention is related to microelectronic imaging units havingsolid-state image sensors and methods for manufacturing such imagingunits.

BACKGROUND

Microelectronic imagers are used in digital cameras, wireless deviceswith picture capabilities, and many other applications. Cell phones andPersonal Digital Assistants (PDAs), for example, are incorporatingmicroelectronic imagers for capturing and sending pictures. The growthrate of microelectronic imagers has been steadily increasing as theybecome smaller and produce better images with higher pixel counts.

Microelectronic imagers include image sensors that use Charged CoupledDevice (CCD) systems, Complementary Metal-Oxide Semiconductor (CMOS)systems, or other solid-state systems. CCD image sensors have beenwidely used in digital cameras and other applications. CMOS imagesensors are also quickly becoming very popular because they are expectedto have low production costs, high yields, and small sizes. CMOS imagesensors can provide these advantages because they are manufactured usingtechnology and equipment developed for fabricating semiconductordevices. CMOS image sensors, as well as CCD image sensors, areaccordingly “packaged” to protect their delicate components and toprovide external electrical contacts.

FIG. 1 is a schematic side cross-sectional view of a conventionalmicroelectronic imaging unit 1 including an imaging die 10, a chipcarrier 30 carrying the die 10, and a cover 50 attached to the carrier30 and positioned over the die 10. The imaging die 10 includes an imagesensor 12 and a plurality of bond-pads 16 operably coupled to the imagesensor 12. The chip carrier 30 has a base 32, sidewalls 34 projectingfrom the base 32, and a recess 36 defined by the base 32 and sidewalls34. The die 10 is accordingly sized to be received within the recess 36and attached to the base 32. The chip carrier 30 further includes anarray of terminals 18 on the base 32, an array of contacts 24 on anexternal surface 38, and a plurality of traces 22 electricallyconnecting the terminals 18 to corresponding external contacts 24. Theterminals 18 are positioned between the die 10 and the sidewalls 34 sothat wire-bonds 20 can electrically couple the terminals 18 tocorresponding bond-pads 16 on the die 10.

One problem with the microelectronic imaging unit 1 illustrated in FIG.1 is that the die 10 must be sized and configured to fit within therecess 36 of the chip carrier 30. Dies having different shapes and/orsizes accordingly require chip carriers configured to house thosespecific types of dies. As such, manufacturing imaging units with dieshaving different sizes requires fabricating various configurations ofchip carriers and significantly retooling the manufacturing process.

Another problem with conventional microelectronic imaging units is thatthey have relatively large footprints and occupy a significant amount ofvertical space (i.e., high profiles). For example, the footprint of theimaging unit 1 in FIG. 1 is the surface area of the base 32 of the chipcarrier 30, which is significantly larger than the surface area of thedie 10. Accordingly, the footprint and vertical profile of conventionalmicroelectronic imaging units can be a limiting factor in the design andmarketability of picture cell phones or PDAs because these devices arecontinually being made smaller in order to be more portable. Therefore,there is a need to provide microelectronic imaging units with smallerfootprints and lower vertical profiles.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side cross-sectional view of a conventionalmicroelectronic imaging unit in accordance with the prior art.

FIGS. 2A-4 illustrate stages in one embodiment of a method formanufacturing a plurality of microelectronic imaging units in accordancewith the invention.

FIG. 2A is a schematic side cross-sectional view of a microfeatureworkpiece having a substrate and a plurality of microelectronic imagingdies formed in and/or on the substrate.

FIG. 2B is a top plan view of the workpiece illustrated in FIG. 2A.

FIG. 3A is a schematic side cross-sectional view of an assemblyincluding singulated microelectronic imaging dies arranged in an arrayon a support member.

FIG. 3B is a top plan view of the assembly illustrated in FIG. 3A.

FIG. 4 is a schematic side cross-sectional view of the assembly after(a) forming a plurality of dams on corresponding imaging dies and (b)depositing a fill material onto the support member between a barrier andthe imaging dies.

FIG. 5 is a schematic side cross-sectional view of an assembly includinga plurality of microelectronic imaging units in accordance with anotherembodiment of the invention.

FIG. 6 is a schematic side cross-sectional view of an imaging unit inaccordance with another embodiment of the invention.

DETAILED DESCRIPTION

A. Overview

The following disclosure describes several embodiments of methods formanufacturing microelectronic imaging units and microelectronic imagingunits that are formed using such methods. One aspect of the invention isdirected toward methods for manufacturing a plurality of imaging units.An embodiment of one such method includes providing a plurality ofimaging dies on a microfeature workpiece. The individual imaging diesinclude an image sensor, an integrated circuit operably coupled to theimage sensor, and a plurality of external contacts operably coupled tothe integrated circuit. The method further includes attaching aplurality of covers to corresponding imaging dies, cutting themicrofeature workpiece to singulate the imaging dies, and coupling thesingulated dies to a support member. The microfeature workpiece can becut before or after the covers are attached to the imaging dies. Thecovers can be attached to the imaging dies with an adhesive that isdisposed outboard the image sensor and defines a cell between the coverand the die. Alternatively, the adhesive can be disposed between thecover and the image sensor.

In another embodiment, a method includes coupling a plurality ofsingulated imaging dies to a support member, placing a plurality ofcovers on corresponding imaging dies with the covers disposed inboard ofthe external contacts of the imaging dies, electrically connecting theexternal contacts to corresponding terminals on the support member, andforming a plurality of dams on corresponding dies. The individual damsare arranged to define a perimeter around the corresponding covers. Themethod may further include forming a barrier on the support memberbetween adjacent dies and depositing a fill material onto the supportmember between the barrier and the imaging dies. The fill material canat least partially encapsulate the imaging dies.

Another aspect of the invention is directed toward a plurality ofmicroelectronic imaging units. In one embodiment, an assembly of imagingunits includes a support member and a plurality of imaging dies carriedby the support member. The support member includes a plurality ofterminal arrays, and the individual imaging dies include a first side, asecond side attached to the support member, an image sensor, anintegrated circuit operably coupled to the image sensor, and a pluralityof external contacts operably coupled to the integrated circuit. Theassembly further includes a plurality of covers attached to the firstside of corresponding dies, a plurality of wire-bonds electricallyconnecting the external contacts to corresponding terminals, and abarrier on the support member between adjacent imaging dies. Theassembly may further include a plurality of dams on corresponding diesand a fill material on the support member between the barrier and theimaging dies. The individual dams form a perimeter around thecorresponding cover and inhibit the fill material from flowing onto thecover.

Another aspect of the invention is directed toward a microelectronicimaging unit. In one embodiment, an imaging unit includes a supportmember having a base, a plurality of sidewalls projecting from the base,a recess defined by the sidewalls and the base, and a plurality ofterminals in the base and/or sidewalls. The imaging unit furtherincludes an imaging die received in the recess and attached to the baseof the support member. The imaging die has an image sensor, anintegrated circuit operably coupled to the image sensor, and a pluralityof external contacts operably coupled to the integrated circuit. Theimaging unit further includes a cover attached to the imaging die, aplurality of wire-bonds electrically connecting the external contacts tocorresponding terminals, and a fill material in the recess between theimaging die and the sidewalls.

Specific details of several embodiments of the invention are describedbelow with reference to CMOS imaging units to provide a thoroughunderstanding of these embodiments, but other embodiments can use CCDimaging units or other types of solid-state imaging devices. Severaldetails describing structures or processes that are well known and oftenassociated with other types of microelectronic devices are not set forthin the following description for purposes of brevity. Moreover, althoughthe following disclosure sets forth several embodiments of differentaspects of the invention, several other embodiments of the invention canhave different configurations or different components than thosedescribed in this section. As such, it should be understood that theinvention may have other embodiments with additional elements or withoutseveral of the elements described below with reference to FIGS. 2A-6.

B. Embodiments of Methods for Manufacturing Microelectronic ImagingUnits

FIGS. 2A-4 illustrate stages of a method for manufacturing a pluralityof microelectronic imaging units in accordance with one embodiment ofthe invention. FIG. 2A, for example, is a schematic side cross-sectionalview of a microfeature workpiece 104 having a substrate 105 and aplurality of microelectronic imaging dies 110 (only three are shown)formed in and/or on the substrate 105. The individual imaging dies 110include an image sensor 112, an integrated circuit 114 (shownschematically) operably coupled to the image sensor 112, and a pluralityof external contacts 116 (e.g., bond-pads) operably coupled to theintegrated circuit 114. The image sensors 112 can be CMOS devices or CCDimage sensors for capturing pictures or other images in the visiblespectrum. The image sensors 112 may also detect radiation in otherspectrums (e.g., IR or UV ranges).

FIG. 2B is a top plan view of the microfeature workpiece 104 illustratedin FIG. 2A. Referring to both FIGS. 2A and 2B, after forming the imagingdies 110, a plurality of covers 150 are attached to corresponding dies110 and positioned over the image sensors 112. The covers 150 can beglass, quartz, or another suitable material that is transmissive to thedesired spectrum of radiation. The covers 150, for example, can furtherinclude one or more anti-reflective films and/or filters. The covers 150include a plurality of ends 151, and although in the illustratedembodiment, the ends 151 are inboard the external contacts 116, in otherembodiments, the ends 151 may not be inboard the external contacts 116.The ends 151 of the covers 150 are inboard the external contacts 116 inthe sense that they are within the perimeters defined by the sets ofexternal contacts 116.

The covers 150 are attached to the imaging dies 110 with an adhesive130. The adhesive 130 has a thickness T (FIG. 2A) and spaces the covers150 apart from the imaging dies 110 by a precise, predetermineddistance. In the illustrated embodiment, the discrete portions of theadhesive 130 are disposed between a perimeter portion of the individualcovers 150 and the dies 110. As such, the discrete portions of theadhesive 130 are positioned outboard the corresponding image sensor 112and inboard the external contacts 116 (e.g., between the image sensor112 and the external contacts 116). In other embodiments, such as thosedescribed below with reference to FIG. 5, the adhesive 130 may also bedisposed between the covers 150 and the image sensors 112.

In the illustrated embodiment, the individual portions of adhesive 130form a perimeter around the corresponding image sensor 112 and define acell 152 (FIG. 2A) between the cover 150 and the image sensor 112. Thecells 152 can be filled with gas, such as air, underfill material, oranother suitable material. In other embodiments, the adhesive 130 maynot form perimeters around the image sensors 112. For example, severaldiscrete volumes of the adhesive 130 can be placed around each imagesensor 112 to couple the corresponding cover 150 to the die 110. Thediscrete volumes of the adhesive 130 can be disposed proximate to thecorners of the covers 150 or positioned in other arrangements.

The adhesive 130 can be an epoxy, acrylic, or other suitable materialthat is applied to the covers 150 and/or the imaging dies 110 by stencilprinting, screen printing, dispensing, photolithography, or othersuitable techniques. In embodiments in which the adhesive 130 is a UV-or thermally-curable material, the workpiece 104 can be heated to atleast partially cure (i.e., B-stage) the adhesive 130 after attachingthe covers 150 to the substrate 105 (FIG. 2A). After curing, theworkpiece 104 can be cut along lines A₁-A₁ (FIG. 2A) to singulate theindividual dies 110.

FIG. 3A is a schematic side cross-sectional view of an assembly 100including the singulated microelectronic imaging dies 110 (only two areshown) arranged in an array on a support member 160. The individualsingulated dies 110 include a first side 111, a second side 113 oppositethe first side 111, and a plurality of ends 115 extending from the firstside 111 to the second side 113. The second side 113 of the imaging dies110 is attached to the support member 160 with an adhesive 120, such asan adhesive film, epoxy, or other suitable material. In severalembodiments, the covers 150 can be attached to the imaging dies 110after the dies 110 are coupled to the support member 160.

The support member 160 can be a lead frame or a substrate, such as aprinted circuit board, for carrying the imaging dies 110. In theillustrated embodiment, the support member 160 includes a first side 162having a plurality of terminals 166 and a second side 164 having aplurality of pads 168. The terminals 166 can be arranged in arrays forattachment to corresponding external contacts 116 of the dies 110, andthe pads 168 can be arranged in arrays for attachment to a plurality ofconductive couplers (e.g., solder balls). The support member 160 furtherincludes a plurality of conductive traces 169 electrically coupling theterminals 166 to corresponding pads 168.

FIG. 3B is a top plan view of the assembly 100 illustrated in FIG. 3A.Referring to both FIGS. 3A and 3B, the assembly 100 further includes aplurality of wire-bonds 140 electrically coupling the external contacts116 of the imaging dies 110 to corresponding terminals 166 on thesupport member 160. The individual wire-bonds 140 include a proximalportion 142 attached to one of the contacts 116 and a distal portion 144attached to the corresponding terminal 166. In other embodiments, theexternal contacts 116 can be electrically connected to terminals on asupport member by conductive through-wafer interconnects. Through-waferinterconnects are described in U.S. patent application Ser. No.10/713,878 filed on Nov. 13, 2003, which is hereby incorporated byreference.

The illustrated assembly 100 further includes a barrier 180 formed onthe support member 160 between adjacent imaging dies 110. The barrier180 forms the outer sidewalls of the individual imaging units, asdescribed in greater detail below. Although in the illustratedembodiment, the barrier 180 is disposed outboard the wire-bonds 140 andthe terminals 166, in other embodiments, the barrier 180 may cover orpartially encapsulate the wire-bonds 140 and/or the terminals 166. Thebarrier 180 can be formed by transfer molding, stereolithography,stencil printing, screen printing, or other suitable processes. Thebarrier 180 projects a first distance D₁ from the support member 160,and the die 110 and cover 150 project a second distance D₂ from thesupport member 160. In the illustrated embodiment, the first distance D₁is greater than the second distance D₂, and the barrier 180 has agenerally flat top surface 182 to which a camera module or other opticaldevice can be mounted. In other embodiments, the first distance D₁ canbe equal to or less than the second distance D₂ and/or the top surface182 may not be generally flat. Alternatively, in several embodimentssuch as those described below with reference to FIG. 5, the assembly 100may not include the barrier 180.

FIG. 4 is a schematic side cross-sectional view of the assembly 100after (a) forming a plurality of dams 190 on corresponding imaging dies110 and (b) depositing a fill material 195 onto the support member 160between the barrier 180 and the imaging dies 110. The illustrated dams190 are formed on the first side 111 of the imaging dies 110 outboardthe covers 150 and inhibit the fill material 195 from flowing onto thecovers 150 and obstructing the passage of radiation through the covers150. As such, the dams 190 project a first distance D₃ from the dies110, and the adhesive 130 and covers 150 project a second distance D₄from the dies 110. The first distance D₃ can be greater than or equal tothe second distance D₄. Moreover, the dams 190 may also encapsulate theends 151 of the covers 150 and/or the proximal portion 142 of theindividual wire-bonds 140. The dams 190 can be an epoxy, polyimide,acrylic, or other suitable material for (a) enhancing the integrity ofthe joint between the individual covers 150 and the imaging dies 110,and (b) protecting the image sensors 112 from moisture, chemicals, andother contaminants. In other embodiments, the dams 190 may notencapsulate the ends 151 of the covers 150 and/or the proximal portion142 of the wire-bonds 140. Alternatively, the assembly 100 may notinclude the dams 190, but rather the fill material 195 can contact theends 151 of the covers 150 and the proximal portion 142 of thewire-bonds 140.

After forming the dams 190, the fill material 195 is dispensed onto thesupport member 160 and fills the recess between the imaging dies 110 andthe barrier 180. The fill material 195 can be an epoxy mold compound orother suitable material to at least partially encapsulate the imagingdies 110, the wire-bonds 140, and the dams 190. As such, the fillmaterial 195 (a) increases the robustness of the assembly 100, (b)supports the wire-bonds 140, and (c) protects the image sensors 112 frommoisture, chemicals, and other contaminants. After depositing the fillmaterial 195, the assembly 100 can be heated to at least partially cure(i.e., B-stage) the fill material 195, the dam 190, and/or the adhesive130. After curing, the assembly 100 can be cut along lines A₂-A₂ tosingulate individual imaging units 102.

One feature of the imaging units 102 illustrated in FIG. 4 is that thecovers 150 are attached to the imaging dies 110 and positioned inboardthe external contacts 116. An advantage of this feature is that thevertical profile or height of the imaging units 102 is reduced. Forexample, the vertical profile of the imaging units 102 is the distancebetween the top of the dam 190 and the second side 164 of the supportmember 160. By contrast, in prior art devices, such as the imaging unit1 illustrated in FIG. 1, the cover 50 is attached to sidewalls 34 andsufficiently spaced apart from the image sensor 12 so that thewire-bonds 20 can extend from the bond-pads 16 to the terminals 18.Another advantage of this feature is that the material cost of thecovers 150 is reduced because the covers 150 are smaller thanconventional covers, such as the cover 50 illustrated in FIG. 1.

Another feature of the imaging units 102 illustrated in FIG. 4 is thatthe barrier 180 has a predetermined height D₁ and a generally flat topsurface 182. An advantage of this feature is that camera modules andother devices can be mounted on the surface 182 and positioned at aprecise distance over the image sensors 112. In prior art devices,camera modules are typically mounted on a stack of several components,each of which introduces greater variance in the height of the stack.For example, in FIG. 1, a camera module can be coupled to the cover 50,which is attached to an adhesive 51, which is coupled to the sidewall34.

One feature of the method for manufacturing imaging units 102illustrated in FIGS. 2A-4 is that the support member 160 can carryimaging dies 110 with different sizes and/or configurations. Anadvantage of this feature is that the method can be easily adapted tohandle various configurations of imaging dies without significantchanges to the fabrication process. Prior art methods, such as themethod required to form the imaging unit 1 described above withreference to FIG. 1, may require significant retooling because the chipcarriers 30 can only carry imaging dies 10 with a certain shape andsize.

Another advantage of the method for manufacturing imaging units 102illustrated in FIGS. 2A-4 is that the method is expected tosignificantly enhance the efficiency of the manufacturing processbecause a plurality of imaging units 102 can be fabricatedsimultaneously using highly accurate and efficient processes developedfor packaging and manufacturing semiconductor devices. This method ofmanufacturing imaging units 102 is also expected to enhance the qualityand performance of the imaging units 102 because the semiconductorfabrication processes can reliably produce and assemble the variouscomponents with a high degree of precision. As such, several embodimentsof the method are expected to significantly reduce the cost forassembling microelectronic imaging units 102, increase the performanceof the imaging units 102, and produce higher quality imaging units 102.

C. Additional Embodiments of Methods for Manufacturing MicroelectronicImaging Units

FIG. 5 is a schematic side cross-sectional view of an assembly 200including a plurality of microelectronic imaging units 202 in accordancewith another embodiment of the invention. The microelectronic imagingunits 202 are generally similar to the microelectronic imaging units 102described above with reference to FIG. 4. The imaging units 202 shown inFIG. 5, however, do not include a barrier between adjacent dies 110.Rather, the fill material 195 fills the space between the adjacentimaging dies 110 and forms the sidewall of the imaging units 202 afterthe units 202 are singulated.

One feature of the imaging units 202 illustrated in FIG. 5 is that thewire-bonds 140 are encapsulated by the fill material 195 that forms thesidewalls of the individual units 202. An advantage of this feature isthat the footprint of the individual imaging units 202 is smaller thanthe footprint of conventional imaging units. The reduced footprint ofthe imaging units 202 is particularly advantageous for picture cellphones, PDAs, or other applications where space is limited. In prior artdevices, such as the imaging unit 1 illustrated in FIG. 1, the sidewalls34 are outboard the terminals 18 and the wire-bonds 20, which increasesthe footprint of the imaging unit 1.

The illustrated assembly 200 further includes discrete portions of anadhesive 230 attaching the covers 150 to corresponding imaging dies 110.The individual portions of the adhesive 230 are disposed between thecovers 150 and the first side 111 of the imaging dies 110 such that theadhesive 230 extends across the image sensors 112. The adhesive 230 canbe an optical grade material with a high transparency to eliminate orreduce light scattering and/or the loss of images. In applications inwhich the image sensors 112 have pixels with a smaller size, theadhesive 230 can have a higher refractive index to assist in focusingthe light for the pixels.

One feature of the imaging units 202 illustrated in FIG. 5 is that theadhesive 230 can be a material that is dimensionally stable over a widerange of temperatures. An advantage of this feature is that the distancebetween the covers 150 and the corresponding image sensors 112 remainsgenerally consistent, even if the imaging units 202 operate in anenvironment that experiences significant changes in ambient temperature.If the temperature change were to cause the medium between the cover 150and the image sensor 112 to expand or contract, the associated change inthe distance between the cover 150 and the image sensor 112 could skewthe images and reduce the life of the imaging unit 202 due to fatigue.

FIG. 6 is a schematic side cross-sectional view of an imaging unit 302in accordance with another embodiment of the invention. Themicroelectronic imaging unit 302 is generally similar to the imagingunit 102 described above with reference to FIG. 4. The imaging unit 302shown in FIG. 6, however, includes a support member 360 having a base361, a plurality of sidewalls 363 projecting from the base 361, and arecess 365 defined by the base 361 and the sidewalls 363. The base 361and sidewalls 363 can be a preformed, unitary member sized to receivethe imaging die 110. As such, the imaging die 110 is received in therecess 365 and attached to the base 361. Another aspect of theillustrated imaging unit 302 is that the unit 302 does not include anadhesive between the cover 150 and the die 110 but rather the dam 190secures the cover 150 to the imaging die 110. In other embodiments,however, the cover 150 can be attached to the imaging die 110 with anadhesive.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thespirit and scope of the invention. For example, the microelectronicimaging units can have any combination of the features described above.Accordingly, the invention is not limited except as by the appendedclaims.

1. A method of manufacturing a plurality of imaging units, the methodcomprising: providing a plurality of imaging dies on a microfeatureworkpiece, the individual imaging dies including an image sensor, anintegrated circuit operably coupled to the image sensor, and a pluralityof external contacts operably coupled to the integrated circuit;attaching a plurality of covers to corresponding imaging dies with thecovers positioned over the image sensors; cutting the microfeatureworkpiece to singulate the imaging dies; and coupling the singulateddies to a single support member having terminals for electricalconnection to the external contacts and pads electrically coupled to theterminals.
 2. The method of claim 1, further comprising: electricallyconnecting the external contacts of the imaging dies to correspondingterminals on the support member; building a barrier between adjacentdies; forming a plurality of dams on corresponding dies after attachingthe covers, the individual dams defining a perimeter around theassociated cover; and depositing a fill material onto the support memberbetween the barrier and the imaging dies to at least partiallyencapsulate the imaging dies.
 3. The method of claim 1 wherein cuttingthe microfeature workpiece occurs after attaching the covers to theimaging dies.
 4. The method of claim 1 wherein attaching the covers tothe imaging dies comprises: depositing discrete portions of an adhesiveonto the covers and/or the imaging dies; and placing the covers on thecorresponding imaging dies such that the individual portions of theadhesive are disposed outboard the image sensor and define a cellbetween the cover and the die.
 5. The method of claim 1 whereinattaching the covers to the imaging dies comprises: depositing discreteportions of an adhesive onto the covers and/or the imaging dies; andplacing the covers on the corresponding imaging dies such that theindividual portions of the adhesive are disposed between the associatedimage sensor and cover.
 6. The method of claim 1 wherein attaching thecovers to the imaging dies comprises coupling the covers to the imagingdies with a UV-curable adhesive.
 7. The method of claim 1, furthercomprising forming a plurality of dams on corresponding dies afterattaching the covers to the dies, the individual dams defining aperimeter around the associated cover.
 8. The method of claim 1, furthercomprising forming a barrier on the support member between adjacentdies.
 9. The method of claim 1, further comprising depositing a fillmaterial onto the support member between adjacent imaging dies to atleast partially encapsulate the imaging dies.
 10. The method of claim 1wherein attaching the covers to the imaging dies comprises coupling thecovers to the imaging dies such that the individual covers are disposedinboard the external contacts.
 11. A method of manufacturing a pluralityof imaging units, the method comprising: coupling a plurality ofsingulated imaging dies to a support member, the individual imaging diescomprising an image sensor, an integrated circuit operably coupled tothe image sensor, and a plurality of external contacts operably coupledto the integrated circuit; placing a plurality of covers oncorresponding imaging dies with the covers disposed inboard the externalcontacts; electrically connecting the external contacts of the imagingdies to corresponding terminals on the support member; and forming aplurality of dams on corresponding dies after placing the covers on theimaging dies, the individual dams defining a perimeter around anassociated cover.
 12. The method of claim 11 wherein placing the coverson the corresponding imaging dies occurs before coupling the dies to thesupport member.
 13. The method of claim 11 wherein: electricallyconnecting the external contacts comprises wire-bonding the externalcontacts to the terminals with a proximal end of the individualwire-bonds attached to the contacts; and forming the dams comprisesencapsulating the proximal end of the individual wire-bonds.
 14. Themethod of claim 11 wherein the covers include a plurality of ends, andwherein forming the dams comprises encapsulating the ends of theindividual covers.
 15. The method of claim 11 wherein placing the coverson the imaging dies comprises: depositing discrete portions of anadhesive onto the covers and/or the imaging dies; and attaching thecovers to the corresponding imaging dies such that the individualportions of the adhesive are disposed outboard the image sensor anddefine a cell between the cover and the die.
 16. The method of claim 11wherein placing the covers on the imaging dies comprises: depositingdiscrete portions of an adhesive onto the covers and/or the imagingdies; and attaching the covers to the corresponding imaging dies suchthat the individual portions of the adhesive are disposed between theassociated image sensor and cover.
 17. The method of claim 11, furthercomprising depositing a fill material onto the support member betweenadjacent imaging dies to at least partially encapsulate the imagingdies.
 18. The method of claim 11, further comprising: forming a barrieron the support member between adjacent dies; and depositing a fillmaterial onto the support member between the barrier and the imagingdies.
 19. A method of manufacturing a plurality of imaging units, themethod comprising: constructing a plurality of imaging dies on amicrofeature workpiece, the individual imaging dies including an imagesensor, an integrated circuit operably coupled to the image sensor, anda plurality of external contacts operably coupled to the integratedcircuit; coupling a plurality of covers to corresponding imaging dieswith the covers positioned over the image sensors; cutting themicrofeature workpiece to separate the imaging dies after coupling thecovers to the imaging dies; attaching the singulated dies to a supportmember; wire-bonding the external contacts of the imaging dies tocorresponding terminals on the support member; and depositing a fillmaterial onto the support member between adjacent imaging dies to atleast partially encapsulate the imaging dies.
 20. The method of claim 19wherein depositing the fill material comprises encapsulating at least aportion of the individual wire-bonds.
 21. The method of claim 19 whereincoupling the covers to the imaging dies comprises: depositing discreteportions of an adhesive onto the covers and/or the imaging dies; andattaching the covers to the corresponding imaging dies such that theindividual portions of the adhesive are disposed outboard the imagesensor and define a cell between the cover and the die.
 22. The methodof claim 19, further comprising forming a plurality of dams oncorresponding dies after coupling the covers to the dies and beforedepositing the fill material, the individual dams defining a perimeteraround the associated cover.
 23. The method of claim 19, furthercomprising forming a barrier on the support member between adjacent diesbefore depositing the fill material.
 24. A method of manufacturing aplurality of imaging units, the method comprising: providing a pluralityof imaging dies on a microfeature workpiece, the individual imaging diesincluding an image sensor, an integrated circuit operably coupled to theimage sensor, and a plurality of external contacts operably coupled tothe integrated circuit; attaching a plurality of covers to correspondingimaging dies with the covers positioned over the image sensors; cuttingthe microfeature workpiece to singulate the imaging dies; coupling thesingulated dies to a support member; electrically connecting theexternal contacts of the imaging dies to corresponding terminals on thesupport member; building a barrier between adjacent dies after attachingthe covers to the dies; and forming a plurality of dams on correspondingdies, the individual dams surrounding the associated cover.
 25. Themethod of claim 24 wherein building the barrier comprises constructingthe barrier with a generally flat top surface.
 26. The method of claim24 wherein building the barrier comprises constructing the barrieroutboard the terminals.
 27. The method of claim 24 wherein: electricallyconnecting the external contacts comprises wire-bonding the externalcontacts to the corresponding terminals; and building the barriercomprises constructing the barrier outboard the wire-bonds.
 28. Themethod of claim 24 wherein forming the dams occurs after (a)electrically connecting the external contacts and the terminals and (b)attaching the covers to the imaging dies.
 29. The method of claim 24wherein: electrically connecting the external contacts compriseswire-bonding the external contacts to the terminals with a proximal endof the individual wire-bonds attached to the contacts; and forming thedams comprises encapsulating the proximal end of the individualwire-bonds.
 30. The method of claim 24 wherein the covers include aplurality of ends, and wherein forming the dams comprises encapsulatingthe ends of the individual covers.
 31. The method of claim 24, furthercomprising depositing a fill material between the barrier and theimaging dies. 32-34. (canceled)
 35. A method of manufacturing an imagingunit, the method comprising: providing a support member having a base, aplurality of sidewalls projecting from the base, and a recess defined bythe sidewalls and the base; coupling an imaging die to the base of thesupport member with the die received within the recess, the imaging dieincluding an image sensor, an integrated circuit operably coupled to theimage sensor, and a plurality of external contacts operably coupled tothe integrated circuit; attaching a cover to the imaging die with thecover positioned over the image sensor; electrically connecting theexternal contacts of the imaging die to corresponding terminals on thesupport member; and depositing a fill material into the recess of thesupport member between the imaging die and the sidewalls to at leastpartially encapsulate the imaging die.
 36. The method of claim 35wherein: electrically connecting the external contacts to the terminalscomprises wire-bonding the contacts to the terminals; and depositing thefill material comprises at least partially encapsulating the individualwire-bonds.
 37. The method of claim 35 wherein attaching the cover tothe imaging die occurs before coupling the imaging die to the supportmember.
 38. The method of claim 35, further comprising forming a dam onthe imaging die, the dam defining a perimeter around the cover.
 39. Themethod of claim 35 wherein attaching the cover comprises coupling thecover such that the cover is inboard the external contacts.
 40. Themethod of claim 35 wherein attaching the cover comprises: depositing anadhesive onto the cover and/or the imaging die; and placing the cover onthe imaging die such that the adhesive is disposed outboard the imagesensor and defines a cell between the cover and the die.
 41. The methodof claim 35 wherein attaching the cover comprises: depositing anadhesive onto the cover and/or the imaging die; and placing the cover onthe imaging die such that the adhesive is disposed between the imagesensor and the cover. 42-82. (canceled)